Discoloured grey/silver hair

I think thats whats caused mine too Mazgg. I certainly won't be bleaching it I did enough of that in my younger years. I actually can't remember the last time I went to a hairdressers. I might try just trying to put the purple toner on the worst bits see how that looks.

My silver/white hair has a yellow tinge at the front due to the sun.

You could get a hairdresser to bleach out the yellow streak or do it yourself.
The yellow colour must be coming from somewhere, so look at what’s causing it?